May 2010 Archive for In the Shop

As a farm machinery mechanic and writer, Dan brings a hands-on approach that only a pro can muster. Along with his In the Shop blog, Dan writes a column by the same name as well as the Shop Series for Farm Journal magazine. Always providing practical information, he is a master at tackling technical topics and making them easy for all of our readers to understand. He and his wife, Becky, live near Bouton, Iowa.

Leaking hydraulic cylinders aren't hard to fix, as long as they aren't: (a) 6-inch diameter by 36-inch long wing-fold cylinders off a mammoth field cultivator or disk, or (b) Wire-Lok-type cylinders that use sometimes tricky internal lock rings to attach the end cap to the cylinder bores.

If the leaky hydraulic cylinder is a simple 3-inch by 12-inch cylinder with the end caps held against the bore by four long "tie-bolts"---it's a piece of cake. With some basic tools and a large dose of patience repairs are straight-forward:

First, identify the make and model of the cylinder and acquire the proper seal kit. Many cylinders have model numbers stamped somewhere on them. Otherwise take the cylinder to your equipment dealer and let the expert at the parts counter decipher what you need.

Second, power wash or use a parts washer to thoroughly clean the exterior of the cylinder--top, bottom, sides and ends. Clean an area of your workbench and cover it with an old feed sack or a layer of paper towels. "Clean" is the byword when working on hydraulic components.

Clamp the cylinder in a bench vise. Use a cold chisel or center punch to make marks on the end cap and cylinder bore so you can reassemble those components in proper alignment. Use an air impact wrench or hand tools to remove the 4 nuts on the tie-bolts that hold the end cap through which the cylinder rods slides in and out. Put a drain pan under the cylinder. Use a hammer to tap the end cap out of the cylinder bore. Once the end cap pops free, pull or tap the clevis on the end of the cylinder shaft to remove the shaft/piston from the cylinder bore.

Carefully lay the shaft/piston assembly on the (clean) bench top and take a deep breath. Note the arrangement of seals, o-rings, backing rings and other sealing components on the end cap and the piston. If necessary, make a sketch on scrap paper of which o-rings and back-up rings go in front of each other. Open the seal repair kit purchased at the dealership and carefully lay out all the o-rings, back-up rings, etc.

Use an impact wrench or hand tools to remove the lock nut that holds the piston to the shaft. Note that there is an o-ring inside the piston. Slide the shaft through the end cap. Note that there are seals/o-rings inside the hole in the end cap. Pay close attention to the orientation/sequence of those o-rings and seals.

Now carefully use a small screwdriver or o-ring pick to systematically remove o-rings and back-up rings and replace them with new ones from the kit. It helps to lay out the old parts in-order, exactly as removed, so you can refer to them about positioning and orientation. Be aware that some "flat" back-up rings actually have one surface that is subtly curved to nestle against its o-ring, and that some back-up rings have chamfered (beveled) edges, so they must be oriented correctly.

Seals in end caps--the ones through which the cylinder rods slides in and out--can be challenges to remove. Use care not to damage the often soft metal of the end cap. A very small cold chisel or sharp metal punch can often help pry out those stubborn metal-framed seals. Before you remove (destroy) the old seals be certain to note the "front" and "back" (inside or outside) of the old seal so you can install the new one correctly.

With all the new seals installed, coat every component with light grease or hydraulic oil and carefully, carefully, slide things back together. As you push the piston into the bore, and as you tap the end cap back into place, use a small screwdriver to gently compress o-rings and seals into their grooves. It often helps to stand the cylinder on end so the weight of the piston and end cap works to slide those components into place--all you have to do is use the mini-screwdriver to compress any protruding seals or o-rings. Even the best mechanic occasionally pinches an o-ring or seal during re-assembly, so don't take it personally if that happens.

Once the piston and end cap are installed, tighten the nuts on the tie-bolts to approximately 200 ft. lbs. Repairing leaky hydraulic cylinders is an oily, sloppy job, and rebuilding mega-cylinders if often a two-man job simply because of the weight and size of the components. But it's not brain surgery, so most farmers can accomplish the repairs themselves if they have patience, a few tools and don't mind getting well-oiled in the process.

There are certain hammers, wrenches and tools that I use more often than other hammers, wrenches and tools I have in my toolbox. Most of the time I can explain logically why I prefer one tool over another. So can other mechanics. For example:

-I like dead-blow ball peen hammers with steel shanks in plastic-coated handles. Dead-blows have cavities in their heads filled with tiny lead shot. When you swing a dead-blow, inertia moves the shot to the top of the cavity, and when you strike an object inertia makes that shot move downward in that cavity a split-second after impact. The result is less rebound and more of the striking force being directed into the object. I like that. I also like the unbreakable handles.

-My co-worker and friend Mark prefers solid-head ball peen hammers with wooden handles. He likes the "feel" and cushioning effect of a wooden handle, and gladly buys and replaces wooden handles that get broken in order to gain the unique feel of a wooden handle.

-I prefer "ear muffs" rather than foam-rubber inserts to protect my ears from loud noises. Ear muffs are clumsy and hot in warm weather, but people don't walk up and start talking to me from behind my back when I'm wearing the highly visible ear muffs.

-I prefer florescent green, orange, even pink handles on my tools whenever possible. I've even painted yellow stripes on many of my black, gray or uncolored tools. It's more difficult to misplace or leave behind a brightly colored tool when working in the dark confines of large equipment.

-I prefer standard pry bars and alignment punches. My pry bars look like giant screwdrivers, with flat tips, from 1- to 6-feet in length. My friend Mark has a thing for "roll-head" pry bars. Some mechanics call them "lady foot" pry bars. I've got a set of lady foot bars, and can only remember using them once in the past 5 years. Mark practically carries one in his back pocket at all times and uses it constantly.

The list goes on. Everybody has favorite tools, and good reasons for exactly why they are favorite tools. Some of the reasons are logical, and some are whimsical. Which brings us to the category of unexplainable tool preferences that verge on fetishes.
For example:

-I'm weird for good, practical, portable shop lights. Every time the tool salesman gets in stock a new type of battery-powered or ultra-bright portable light, he knows I'm a sucker that will probably buy one. I dislike dim lights, I dislike dragging power cords around, and I dislike lights that put out a lot of heat or have potential to brand my arm if I brush them by accident. Someday I'll find my dream shop light.

-I have a "thing" for Vise-Grip lockjaw pliers. Not Vise-Grip-type pliers. I can only stomach the ones that have "Vise-Grip" stamped on the handles.. Do I need four pairs of 9-inchers, two 16-inchers, three 6-inchers, four needlenose of various sizes, and a dozen or more odd-jawed Vise-Grip pliers? No. But I do, and I want more.

Every mechanic, every farmer, has tools they "like" more than similar tools. Maybe it's because that tool fits or balances well in their hand. Maybe because it serves a unique purpose well. Maybe it's because they're just a little weird for certain tools.

Stoltzie was uniquely gifted. He was a natural mechanic, one of those guys who somehow always understood how all the pieces should fit together. Faced with a unique or unusual repair on a machine, he would walk around the machine, muttering,patting the machine with his hand, "discussing" with himself what it would take to figure out and fix the problem. We often joked in the shop that Stoltzie could walk up to a machine and "lay hands on it" and, like some sort of mechanical faith healer, immediately know what ailed the machine.

Beyond his rare talents as a mechanic, he had a work ethic second to none. He worked ungodly hours, averaging 10- to 12 hours a day through the "off" season and often tallying 16 or more hours per day during the busy season. To our knowledge, he never turned down a customer's request to fix a machine, no matter what day or what time. More than once he walked away from a family gathering on a Sunday afternoon to fix an ailing baler or a malfunctioning combine. He considered his customers friends, and vowed never to disappoint a friend in need.

Stoltzie was diagnosed with blood cancer in late 2008. He spent last year gamely enduring blood transfusion after blood transfusion, along with agonizing treatments. He often drifted through our shop, checking to see if we were taking care of "his guys" properly. They weren't customers; they were "his guys".

Before he became ill, Stoltzie and I often talked about the future. We both were working our fannies off, putting in as many hours as possible to make as much money as possible, saving for retirement. We agreed it was tough, but that the payoff after we reached retirement would be worth it. He was six years older than me, and our joking plan was that he would retire before me, buy a boat and figure out all the good fishing holes. Then when I retired, I'd buy my own fishing boat and he'd show me how to enjoy retirement.

Last summer on one of his visits, he cornered me. "Hey, Buddy," he said. (Everybody was "Buddy" to Stoltzie. It saved having to remember names.) "Remember how you and me always talked about working hard now, so we could slow down and enjoy life after we retired?" I nodded. "I'll tell you what," he said. "Don't wait. If you have to choose between fixing a combine on a Sunday afternoon and spending time with your family, apologize to the customer and spend time with your family. I'm kinda thinking now that there's more to life than working." He paused, then pointed at me. "And don't wait till you retire to buy that fishing boat."

I thought about Stoltzie a lot this evening, as I tinkered with the fishing boat I bought shortly after that conversation. Work is good, work is important, but there's more to life than work.

Bigger planters and sprayers are hydraulic and electrical hogs. Each spring, we get calls from farmers with planters and sprayers that perform intermittently or have some functions that won't perform at all. Diagnosis reveals the problem is inadequate hydraulic or electrical capacity.

An example: A customer called complaining the wings were drooping on his new 16-row vacuum-type planter with hydraulically driven variable-rate drive. His description of the problem over the phone made no sense, but once I got to his farm and saw the planter hooked to a 30-year-old tractor, the problem was evident -- not enough hydraulic capacity. The tractor didn't have a big enough hydraulic pump to power the orbital motors, the vacuum fans, the variable-rate drive motors and still have enough oil volume and pressure to fully raise and lower the planter.

I ran into a similar scenario when a customer with an older self-propelled sprayer installed an automatic boom leveling system on his sprayer. Long story short, we eventually determined the constant hydraulic adjustment of boom height by the automatic boom leveling system overloaded the machine's hydraulic system.

Electrical systems on modern equipment are also running at full capacity. Older tractors pulling 16- or 24-row planters at night -- with all the lights on, the radio on, the cab fan on -- may not have the electrical "oomph" to also power any electrical clutches to shut off the planter units on the wings when planting on point rows. This is especially true if customers add electrically powered row shutoff systems that turn on or off multiple rows at a time. When they pull onto end rows and all 16 or 24 rows "fire" at one time, it puts a tremendous load on the tractor's electrical system.

Bottom line: More than ever, farm equipment must be viewed as a "system," from the front of the tractor to the back of the planter, sprayer or other implement. The hydraulic and electrical capacity of tractors and self-propelled units must be matched to the implements they pull. Most dealership salesmen have grown wise to the importance of matching equipment, but if a farmer buys equipment over the Internet, through classified ads or at a farm sale, the burden is on the buyer to make certain his machinery has enough oil and juice to do the job.

I have several tools that are part of my pocket-slapping routine before I leave the house each morning. I've got to have my 8-inch pocket pliers in their holster, my mini-ViseGrips on the other side of my belt, and a motley array of pens, pocket magnets and pocket screwdrivers in my shirt pockets.

Some of you won't leave home without a pocketknife. Others feel naked without a Leatherman or some sort of multi-tool clipped to their belt. The younger generation considers a Palm Pilot or Blackberry an "essential tool", and I confess that I'm starting to feel a little under-equipped if I leave home with my cell phone.

But what is the tool I find most essential? My first thought was the pliers. They hold things, they pound things, they pull things, they pry things, and they make a dandy paperweight when trying to read tech books on windy days. A good pair of pliers with jaws that mesh well and handles that don't flex are like having a third hand.

I gave brief consideration to the mini-ViseGrips, the extendable pocket magnet and the pencil flashlight I carry. The mini-Grips not only salvage a lot of rounded-off nuts and bolts, but help keep my pants balanced--pliers on one side of my belt, mini-Grips on the other. Smart people say that "balance" is important in a person's life, and I heartily agree.

The extendable pocket magnet is important for someone as clumsy and fumble-fingered as I am. I frequently drop nuts and bolts and small tools to the ground or into machinery I'm working on, and the extendable magnet saves a lot of reaching and bending over to retrieve them. The extendable feature is also great for scratching itches between my shoulder blades that I can't quite reach with my hand.

The pencil flashlight was in serious contention for my "most valuable tool". The one I use is literally pencil-sized, powered by 3 AAA batteries, and uses a special LED bulb to produce an amazingly bright, white light. Being able to peer into cavities and better see what I'm working on makes it one of my favorite tools.

But the tool that I feel lost without is a little pocket screwdriver. Almost every professional mechanic has a worn, battered mini-screwdriver tucked into their shirt pocket. My mini-screwdriver opens plastic parts bags, scrapes grease out of crevices, punctures things that need punctured, and is great for cleaning fingernails. Sometimes I even use it as a screwdriver.

I keep duplicates of very few tools. I have a few extra wrenches of common sizes, in case I lose or misplace one. I have a spare pencil flashlight so I'll never be completely in the dark. But secreted in one of my toolbox drawers are four more mini-screwdrivers. A man can never have too many of a great tool.

More and more farmers run roller chains on planters, balers, combines and other machinery "dry". One farmer commented after I recommended replacing all the major drive chains on his combine (a $400 expense), "For the mess it makes and the time it takes (to oil chains daily), I just replace the chains every year and don't worry about it."

I understand and appreciate his view. It certainly makes my job easier and less messy when I work on "dry" chains rather than dripping, oily chains. In some cases I actually advocate running chains dry, but in most cases chains work better and last longer if lubricated regularly.

In no particular order, here are some tips, opinions and ideas about roller chain maintenance:

-seed unit drive chains in planters can usually be run dry. They're low-speed chains that don't build heat and don't run under a lot of tension. Lubrication actually attracts dust and grit that forms an abrasive paste that may speed chain wear. Slow moving, dry chains seem to shed that dust/grit more easily. All bets are off if the planter sits out in the rain--dry chains rust five times faster than chains that have been kept even occasionally lubed.

-Any planter chain that has a kink or stiff spot in it should be replaced. Anybody who runs kinked chains with the attitude, "They'll loosen up after 10 or 15 acres," is harming his plant population and spacing.

-Soak all planter drive chains with clinging, foam-type chain lube prior to annual storage. If a planter has to set outside all year, either remove all chains and store indoors, or plan on replacing all chains annually.

-Round baler drive chains and chains on combines run at high speed and run hotter because of it. Those high-speed chains merit regular lubrication and benefit from it because they sling off excess lubrication and don't "attract" abrasive dust and grit. High-speed chains don't need to drip oil. As long as they're at least "moist" with an oily film, they're happy.

-Chains don't "stretch". Any "stretch" that develops over time in a roller chain is actually the total of fractions of an inch of wear between each of the rollers, sideplates and internal pins. Pins get smaller in diameter, sideplates wear thinner, rollers become narrower. Chains eventually break because their components wear too thin to withstand the load.

-Worn chains create worn sprockets. This can create significant problems on planters if sprocket teeth become so "hooked" that chain links jerk as they come off those hooked teeth. Any jerks or impacts in seeding mechanisms can create seeding skips or misplacement.

-Final opinion: Anybody who puts away a machine for the year with dry chains deserves the cost of replacing those chains.